/*
 * Copyright (c) 2009 Kathryn Huxtable and Kenneth Orr.
 *
 * This file is part of the SeaGlass Pluggable Look and Feel.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 * $Id: SeaGlassButtonUI.java 752 2010-01-16 19:19:55Z kathryn@kathrynhuxtable.org $
 */
package com.seaglasslookandfeel.ui;

import java.awt.Dimension;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.Rectangle;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import javax.swing.AbstractButton;
import javax.swing.ButtonModel;
import javax.swing.Icon;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.LookAndFeel;
import javax.swing.plaf.ComponentUI;
import javax.swing.plaf.UIResource;
import javax.swing.plaf.basic.BasicButtonUI;
import javax.swing.plaf.basic.BasicHTML;
import javax.swing.plaf.synth.ColorType;
import javax.swing.plaf.synth.Region;
import javax.swing.plaf.synth.SynthConstants;
import javax.swing.plaf.synth.SynthContext;
import javax.swing.plaf.synth.SynthGraphicsUtils;
import javax.swing.plaf.synth.SynthLookAndFeel;
import javax.swing.plaf.synth.SynthStyle;
import javax.swing.text.View;

import com.seaglasslookandfeel.SeaGlassContext;
import com.seaglasslookandfeel.SeaGlassLookAndFeel;

import sun.swing.plaf.synth.SynthUI;

/**
 * SeaGlassButtonUI implementation.
 * 
 * Based on SynthButtonUI by Scott Violet.
 * 
 * @see javax.swing.plaf.synth.SynthButtonUI
 */
public class SeaGlassButtonUI extends BasicButtonUI implements PropertyChangeListener, SynthUI {
    private static final String APPLE_PREFIX = "JButton.";
    private SynthStyle          style;

    public static ComponentUI createUI(JComponent c) {
        return new SeaGlassButtonUI();
    }

    protected void installDefaults(AbstractButton b) {
        updateStyle(b);

        LookAndFeel.installProperty(b, "rolloverEnabled", Boolean.TRUE);
    }

    protected void installListeners(AbstractButton b) {
        super.installListeners(b);
        b.addPropertyChangeListener(this);
    }

    public void updateStyle(AbstractButton b) {
        SeaGlassContext context = getContext(b, SynthConstants.ENABLED);
        SynthStyle oldStyle = style;
        style = SeaGlassLookAndFeel.updateStyle(context, this);
        if (style != oldStyle) {
            if (b.getMargin() == null || (b.getMargin() instanceof UIResource)) {
                Insets margin = (Insets) style.get(context, getPropertyPrefix() + "margin");

                if (margin == null) {
                    // Some places assume margins are non-null.
                    margin = SeaGlassLookAndFeel.EMPTY_UIRESOURCE_INSETS;
                }
                b.setMargin(margin);
            }

            Object value = style.get(context, getPropertyPrefix() + "iconTextGap");
            if (value != null) {
                LookAndFeel.installProperty(b, "iconTextGap", value);
            }

            value = style.get(context, getPropertyPrefix() + "contentAreaFilled");
            LookAndFeel.installProperty(b, "contentAreaFilled", value != null ? value : Boolean.TRUE);

            value = b.getClientProperty(APPLE_PREFIX + "buttonType");
            if (value != null) {
                if ("segmented".equals(value)) {
                    b.setMargin(SeaGlassLookAndFeel.EMPTY_UIRESOURCE_INSETS);
                }
            }

            if (oldStyle != null) {
                uninstallKeyboardActions(b);
                installKeyboardActions(b);
            }
        }
        context.dispose();
    }

    protected void uninstallListeners(AbstractButton b) {
        super.uninstallListeners(b);
        b.removePropertyChangeListener(this);
    }

    protected void uninstallDefaults(AbstractButton b) {
        SeaGlassContext context = getContext(b, ENABLED);

        style.uninstallDefaults(context);
        context.dispose();
        style = null;
    }

    public SeaGlassContext getContext(JComponent c) {
        return getContext(c, getComponentState(c));
    }

    SeaGlassContext getContext(JComponent c, int state) {
        Region region = getRegion(c);
        return SeaGlassContext.getContext(SeaGlassContext.class, c, region, style, state);
    }

    private Region getRegion(JComponent c) {
        return SynthLookAndFeel.getRegion(c);
    }

    /**
     * Returns the current state of the passed in <code>AbstractButton</code>.
     */
    private int getComponentState(JComponent c) {
        int state = ENABLED;

        if (!c.isEnabled()) {
            state = DISABLED;
        }
        if (SeaGlassLookAndFeel.selectedUI == this) {
            return SeaGlassLookAndFeel.selectedUIState | SynthConstants.ENABLED;
        }
        AbstractButton button = (AbstractButton) c;
        ButtonModel model = button.getModel();

        if (model.isPressed()) {
            if (model.isArmed()) {
                state = PRESSED;
            } else {
                state = MOUSE_OVER;
            }
        }
        if (model.isRollover()) {
            state |= MOUSE_OVER;
        }
        if (model.isSelected()) {
            state |= SELECTED;
        }
        if (c.isFocusOwner() && button.isFocusPainted()) {
            state |= FOCUSED;
        }
        if ((c instanceof JButton) && ((JButton) c).isDefaultButton()) {
            state |= DEFAULT;
        }
        return state;
    }

    public int getBaseline(JComponent c, int width, int height) {
        if (c == null) {
            throw new NullPointerException("Component must be non-null");
        }
        if (width < 0 || height < 0) {
            throw new IllegalArgumentException("Width and height must be >= 0");
        }
        AbstractButton b = (AbstractButton) c;
        String text = b.getText();
        if (text == null || "".equals(text)) {
            return -1;
        }
        Insets i = b.getInsets();
        Rectangle viewRect = new Rectangle();
        Rectangle textRect = new Rectangle();
        Rectangle iconRect = new Rectangle();
        viewRect.x = i.left;
        viewRect.y = i.top;
        viewRect.width = width - (i.right + viewRect.x);
        viewRect.height = height - (i.bottom + viewRect.y);

        // layout the text and icon
        SeaGlassContext context = getContext(b);
        FontMetrics fm = context.getComponent().getFontMetrics(context.getStyle().getFont(context));
        context.getStyle().getGraphicsUtils(context).layoutText(context, fm, b.getText(), b.getIcon(), b.getHorizontalAlignment(),
            b.getVerticalAlignment(), b.getHorizontalTextPosition(), b.getVerticalTextPosition(), viewRect, iconRect, textRect,
            b.getIconTextGap());
        View view = (View) b.getClientProperty(BasicHTML.propertyKey);
        int baseline;
        if (view != null) {
            baseline = BasicHTML.getHTMLBaseline(view, textRect.width, textRect.height);
            if (baseline >= 0) {
                baseline += textRect.y;
            }
        } else {
            baseline = textRect.y + fm.getAscent();
        }
        context.dispose();
        return baseline;
    }

    // ********************************
    // Paint Methods
    // ********************************

    public void update(Graphics g, JComponent c) {
        SeaGlassContext context = getContext(c);

        SeaGlassLookAndFeel.update(context, g);
        paintBackground(context, g, c);
        paint(context, g);
        context.dispose();
    }

    public void paint(Graphics g, JComponent c) {
        SeaGlassContext context = getContext(c);
        paint(context, g);
        context.dispose();
    }

    protected void paint(SeaGlassContext context, Graphics g) {
        AbstractButton b = (AbstractButton) context.getComponent();

        g.setColor(context.getStyle().getColor(context, ColorType.TEXT_FOREGROUND));
        g.setFont(style.getFont(context));
        context.getStyle().getGraphicsUtils(context).paintText(context, g, b.getText(), getIcon(b), b.getHorizontalAlignment(),
            b.getVerticalAlignment(), b.getHorizontalTextPosition(), b.getVerticalTextPosition(), b.getIconTextGap(),
            b.getDisplayedMnemonicIndex(), getTextShiftOffset(context));
    }

    void paintBackground(SeaGlassContext context, Graphics g, JComponent c) {
        if (((AbstractButton) c).isContentAreaFilled()) {
            context.getPainter().paintButtonBackground(context, g, 0, 0, c.getWidth(), c.getHeight());
        }
    }

    public void paintBorder(SynthContext context, Graphics g, int x, int y, int w, int h) {
        ((SeaGlassContext) context).getPainter().paintButtonBorder(context, g, x, y, w, h);
    }

    /**
     * Returns the default icon. This should NOT callback to the JComponent.
     * 
     * @param b
     *            AbstractButton the iocn is associated with
     * @return default icon
     */

    protected Icon getDefaultIcon(AbstractButton b) {
        SeaGlassContext context = getContext(b);
        Icon icon = context.getStyle().getIcon(context, getPropertyPrefix() + "icon");
        context.dispose();
        return icon;
    }

    /**
     * Returns the Icon to use in painting the button.
     */
    protected Icon getIcon(AbstractButton b) {
        Icon icon = b.getIcon();
        ButtonModel model = b.getModel();

        if (!model.isEnabled()) {
            icon = getSynthDisabledIcon(b, icon);
        } else if (model.isPressed() && model.isArmed()) {
            icon = getPressedIcon(b, getSelectedIcon(b, icon));
        } else if (b.isRolloverEnabled() && model.isRollover()) {
            icon = getRolloverIcon(b, getSelectedIcon(b, icon));
        } else if (model.isSelected()) {
            icon = getSelectedIcon(b, icon);
        } else {
            icon = getEnabledIcon(b, icon);
        }
        if (icon == null) {
            return getDefaultIcon(b);
        }
        return icon;
    }

    /**
     * This method will return the icon that should be used for a button. We
     * only want to use the synth icon defined by the style if the specific icon
     * has not been defined for the button state and the backup icon is a
     * UIResource (we set it, not the developer).
     * 
     * @param b
     *            button
     * @param specificIcon
     *            icon returned from the button for the specific state
     * @param defaultIcon
     *            fallback icon
     * @param state
     *            the synth state of the button
     */
    private Icon getIcon(AbstractButton b, Icon specificIcon, Icon defaultIcon, int state) {
        Icon icon = specificIcon;
        if (icon == null) {
            if (defaultIcon instanceof UIResource) {
                icon = getSynthIcon(b, state);
                if (icon == null) {
                    icon = defaultIcon;
                }
            } else {
                icon = defaultIcon;
            }
        }
        return icon;
    }

    private Icon getSynthIcon(AbstractButton b, int synthConstant) {
        return style.getIcon(getContext(b, synthConstant), getPropertyPrefix() + "icon");
    }

    private Icon getEnabledIcon(AbstractButton b, Icon defaultIcon) {
        if (defaultIcon == null) {
            defaultIcon = getSynthIcon(b, SynthConstants.ENABLED);
        }
        return defaultIcon;
    }

    private Icon getSelectedIcon(AbstractButton b, Icon defaultIcon) {
        return getIcon(b, b.getSelectedIcon(), defaultIcon, SynthConstants.SELECTED);
    }

    private Icon getRolloverIcon(AbstractButton b, Icon defaultIcon) {
        ButtonModel model = b.getModel();
        Icon icon;
        if (model.isSelected()) {
            icon = getIcon(b, b.getRolloverSelectedIcon(), defaultIcon, SynthConstants.MOUSE_OVER | SynthConstants.SELECTED);
        } else {
            icon = getIcon(b, b.getRolloverIcon(), defaultIcon, SynthConstants.MOUSE_OVER);
        }
        return icon;
    }

    private Icon getPressedIcon(AbstractButton b, Icon defaultIcon) {
        return getIcon(b, b.getPressedIcon(), defaultIcon, SynthConstants.PRESSED);
    }

    private Icon getSynthDisabledIcon(AbstractButton b, Icon defaultIcon) {
        ButtonModel model = b.getModel();
        Icon icon;
        if (model.isSelected()) {
            icon = getIcon(b, b.getDisabledSelectedIcon(), defaultIcon, SynthConstants.DISABLED | SynthConstants.SELECTED);
        } else {
            icon = getIcon(b, b.getDisabledIcon(), defaultIcon, SynthConstants.DISABLED);
        }
        return icon;
    }

    /**
     * Returns the amount to shift the text/icon when painting.
     */
    protected int getTextShiftOffset(SeaGlassContext state) {
        AbstractButton button = (AbstractButton) state.getComponent();
        ButtonModel model = button.getModel();

        if (model.isArmed() && model.isPressed() && button.getPressedIcon() == null) {
            return state.getStyle().getInt(state, getPropertyPrefix() + "textShiftOffset", 0);
        }
        return 0;
    }

    // ********************************
    // Layout Methods
    // ********************************
    public Dimension getMinimumSize(JComponent c) {
        if (c.getComponentCount() > 0 && c.getLayout() != null) {
            return null;
        }
        AbstractButton b = (AbstractButton) c;
        SeaGlassContext ss = getContext(c);
        Dimension size = ss.getStyle().getGraphicsUtils(ss).getMinimumSize(ss, ss.getStyle().getFont(ss), b.getText(), getSizingIcon(b),
            b.getHorizontalAlignment(), b.getVerticalAlignment(), b.getHorizontalTextPosition(), b.getVerticalTextPosition(),
            b.getIconTextGap(), b.getDisplayedMnemonicIndex());

        ss.dispose();
        return size;
    }

    public Dimension getPreferredSize(JComponent c) {
        if (c.getComponentCount() > 0 && c.getLayout() != null) {
            return null;
        }
        AbstractButton b = (AbstractButton) c;
        SeaGlassContext ss = getContext(c);
        SynthStyle style2 = ss.getStyle();
        SynthGraphicsUtils graphicsUtils = style2.getGraphicsUtils(ss);
        Dimension size = graphicsUtils.getPreferredSize(ss, style2.getFont(ss), b.getText(), getSizingIcon(b), b.getHorizontalAlignment(),
            b.getVerticalAlignment(), b.getHorizontalTextPosition(), b.getVerticalTextPosition(), b.getIconTextGap(), b
                .getDisplayedMnemonicIndex());

        ss.dispose();
        return size;
    }

    public Dimension getMaximumSize(JComponent c) {
        if (c.getComponentCount() > 0 && c.getLayout() != null) {
            return null;
        }

        AbstractButton b = (AbstractButton) c;
        SeaGlassContext ss = getContext(c);
        Dimension size = ss.getStyle().getGraphicsUtils(ss).getMaximumSize(ss, ss.getStyle().getFont(ss), b.getText(), getSizingIcon(b),
            b.getHorizontalAlignment(), b.getVerticalAlignment(), b.getHorizontalTextPosition(), b.getVerticalTextPosition(),
            b.getIconTextGap(), b.getDisplayedMnemonicIndex());

        ss.dispose();
        return size;
    }

    /**
     * Returns the Icon used in calculating the pref/min/max size.
     */
    protected Icon getSizingIcon(AbstractButton b) {
        // NOTE: this is slightly different than BasicButtonUI, where it
        // would just use getIcon, but this should be ok.
        Icon icon = (b.isEnabled() || b.getDisabledIcon() == null) ? b.getIcon() : b.getDisabledIcon();
        if (icon == null) {
            icon = getDefaultIcon(b);
        }
        return icon;
    }

    public void propertyChange(PropertyChangeEvent e) {
        if (SeaGlassLookAndFeel.shouldUpdateStyle(e)) {
            updateStyle((AbstractButton) e.getSource());
        }
    }
}
